Contactor



Sept. 15, 1959 R. L. CLARK CONTACTOR 2 Sheets-Sheet 1 Filed March 3, 1958 INVENTOR 4 c Wv/ 7% BY Q P 2 4 ,ZATTQRNEY iihik R. L. CLARK Sept. 15, 1959 CONTACTOR 2 Sheets-Sheet 2 Filed March 3, 1958 INVENTOR M/ (J/ATTORNEY United States Patent CONTACTOR Robert L. Clark, New City, N.Y., assignor to Ward Leonard Electric Co., Mount Vernon, N.Y., a corporation of New York Application March 3, 1958, Serial No. 718,618 6 Claims. (Cl. 200104) This invention relates to electromagnetically operated multi-pole contactors which maintain the position of the contacts on application of a severe extraneous mechanical shock.

An object of this invention is to provide a balanced contactor which responds promptly upon an electromagnetic actuation and maintains an open or closed position of the contacts on application of a severe physical shock.

Other and further objects of the invention will become apparent from the following description taken in connection with the drawings in which Fig. 1 illustrates a front view of the contactor;

Fig. 2 is a sectional view of the contactor taken along lines 22 of Fig. 1;

Fig. 3 is a fragmentary view illustrating the balanced mechanism and the maintaining contacts;

Fig. 4 is a sectional view of the electromagnetic unit support taken along lines 44 of Fig. 2;

Fig. 5 is a sectional view of the linkage mechanism coupling the plunger and the counterweight taken along lines -55 of Fig. 2; and

Fig. 6 is a sectional view of the maintaining contacts taken along lines 6-6 of Fig. 1.

In the embodiment illustrated in Figs. 1 and 2 of the drawings the main components of the contactor are a mounting panel 10 with a fixed contact head 11 and a fixed electromagnetic unit 12 with a plunger mechanism 13 for moving the movable bridge contacts .14 in and out of engagement. A counterweight mechanism 15 is slideably mounted behind the electromagnetic unit 12 and actuates the splitter contact 16 mounted on the fixed contact head 11 (Fig. 3).

The fixed contact head 11 comprises a single molded insulating piece 17 formed in this embodiment for a three-pole switch. The insulating piece has chambers 18 for recessing the contacts 24 and 25 within the insulating piece and through which the movable contacts 14 pass. The contacts 24 and 25 are mounted on terminals 20a and 20b, respectively. The terminals have an L- shape with the short legs 23a and 23b bearing the contacts 24 and 25. The legs 23a and 23b seat against a portion of the upper wall of the chamber 18 to receive the force of the contact 14. Slots 19a and 1% are provided in the head and the leg portions 23c and 23d extend through the slots to provide for external connection. The terminals are securely fastened in place by bolts 28:: and 28b.

The contact head member is fastened to the mounting plate 10 by means of bolts 29 passing through the slots 30 and 3:1 in the upper and lower portions of the contact head. The bolts draw the contact head into tight engage.- ment with the panel 10 to securely hold the contact head in place during operation. Front partitions 32 and side partitions 33 are provided to confine any arcs occurring between the contacts within a chamber.

The electromagnetic unit is supported by a generally U-shaped mounting member 36 (Fig. 4) having flanges 'ice 37 for fastening the mounting to the panel 10. The elec-- tromagnetic unit comprises an electromagnetic coil 40,. an armature 42 and a laminated core 48 and forms a solenoid. The core is rectangular in shape and has fourlegs forming an opening 39 for receiving an electromagnetic coil 40. The lower leg has an opening in which the armature 42 is reciprocally positioned. Upper mounting brackets 43 and 44 and lower mounting brackets 45 and 46 are provided for fastening the assembly together and for connecting it to the mounting panel 10 by means of the bracket 36. The U-shaped mounting member 36 forms a chamber 47 spacing the electromagnetic unit from the mounting panel 10.. The supporting member 36 is secured to said panel by means of bolts 53. The supporting member 36'has turned ends or flanges 67 for fastening the electromagnetic unit to the supporting member 36 by means of rivets 68. The electromagnetic coil 40 fits within the laminated core 48. The coil is wound to provide a flux passing through the legs of the core and the armature 42 and has a generally rectangular bore '56 for receiving the armature 42. The coil is retained in position by means of insulating members 49 and 50 positioned in the top and bottom of the coil, respectively, and by a spring wedge '54 fitting between the lower legs of the core and the insulating piece 50 to securely retain the electromagnetic coil in the core without vibration or movement. The spring wedge is made of annealed spring steel and has a U-shape with the legs extending on opposite sides of the armature 42, The legs of the spring wedge are curved With the center portion pressing against the legs of the core and the ends against the insulating piece. The rear ends of the legs are slightly crimped to catch the spring wedge on the legs of the core and curved to press against the insulating member. The front edge is turned to form a portion generally normal to the wedge to stiffen the center leg and provide a means for easily inserting and securing the wedge.

The armature 42 has a laminated structure with a center leg 58 and a cross leg 59 and forms a plunger for operating the electrical contacts. The legs are dimensioned so that when the armature is drawn into the coil, the leg 59 is brought adjacent to the lower leg of the core 48 and the upper end of the leg '58 is brought adjacent to the upper leg of the core to provide a magnetic path for the flux of the coil 40. On opposite sides of the laminated structure are generally T-shaped straps 60; The center legs 61 of the straps are longer than the legs 58 of the laminated structure and extend up through the openings 43a and 44a in the upper mounting brackets 43 and 44 and are secured to the movable contact member 62 by means of the bolt 63. The cross member 64 has a generally triangular space to form portion 64a between which a link 65 may be pivotally connected by the pin or n'vet 66 for connecting the armature to the counterweight mechanism 15. Thus, the armature is connected at one end to the movable contact and at the other end to the counterweight mechanism so that the contacts and the counterweight mechanism move together.

The movable contact member 62 comprises an insulating member 70 secured to the upper ends of the legs 61. The ends of the legs fit in recesses and are firmly secured to the insulating member 70 by a bolt extending through one leg and the member and threaded in the opposite leg to rigidly fasten the insulating member to the armature. The three electrical transfer means on the upper side of the member each comprise a post 71, and a contact bar 72 with contacts 73 and 74 spot welded thereto. A helical spring 77 is fitted around the post and presses upward against the contact bar 72 to press the bar 72 against the retaining washer 78 fitting in a groove at the end of the post. Collars 75 and 76 are provided to movable contacts. A recess 22: is provided in the fixed insulating head between the contacts 24 and25 into which the post 71- projects as the contact bar is forced down the post 71 on the engaging action. The springsv provide the proper contacting force between the fixed and movable contacts. The compression of. the spring main-' tains the contact in engagement for a short period after the plunger commences the downward movement. Thus, in response to the energization of the coil 40 the contacts 24 and 25 are bridged by the contact bar 72 and the circuit is completed for carrying the current. The contactsremain in engagement during the energization of the coil 40 and on de'energization of the coil the movable contact disengages. The movable contacts should remain either in the engaged or disengaged position.

In order to maintain the contacts in the desired position during application of extraneous mechanical shock the weight of a movable armature and contact member is counterbalanced by the counterweight mechanism 15. Thismechanism comprises a weight 80 having a generally rectangular shape with a slot 81. Lateral bore 83 is provided on both sides of the slot 81. The mounting member 36 has sides spacing the electromagnetic unit from the panel to provide a chamber 56 in which the counterweight 80 is located. Guide channels 69 are provided on opposite sides of the chamber and extend parallel to the movement of the plunger. The guides are U-shaped in cross section and have a length greater than the movement of the weight. The member 80 is slidably mounted in the channels 69 and linearly guided by the sides of the guides in a plane parallel to the movement of the armature. A connecting member 85 has one end fitting in the slot 81 and is pivotally connected to the weight 80 by means of a pin 86 extending through the bore 83. The connecting member 85 is connected to the armature by means of the rocker link 87. The rocker link 87 is pivotally mounted on the bracket 88 which is fastened to the panel 10.

The bracket 88 is of a generally U-shape and is formed from a cold rolled sheet steel. Flanges 39 and 90 extend normal to the side portions 92 and 93 and are fastened to the panel by means of bolts 91. A shaft 94 is mounted in the sides 92 and 93 and retained in the bracket 88 by means of retaining rings 95 and 96. The link 87 is formed in two identical parts 87a and 87b which are positioned on opposite sides of the connecting member 85 and the pivotally mounted link 65 and issecured to a respective member by means of pins 97 and 98 held axially in position by locking pins 99. Thus, the link 87 rocks about the shaft 94 as the armature and weight move linearly up and down. The members 87a and 871) have rectangular slots 100a and 10% through which the pins 97 and 98 pass to permit longitudinal sliding of the pins in relation to the link 87. The movable contacts are biased in a normally open position by means of torsion type springs 101 and 102. The springs are positioned around the shaft 94 and have hooked ends 10 1a and 10211 fitting in notches 92a and 93a in the respective sides of the bracket 88 and hooked ends NM and 102b engaging the under edges of the members 87a and 87b of the link 87. The hooks 1011) and 102b engage the link 87 on the opposite side of the shaft 94 from the armature. Thus, the springs 101 and 102 tend to force the weight 80 upWard and draw the armature downward.

The splitter contact 16 is mounted on the side of the fixed contact head 11 and comprises insulating members 103 and 104 forming an internal chamber 105 in which split contacts 106, 107, 108 and 109 are fastened to the insulating member 103. A rectangular shaft 110 ex-- tends through the chamber 105 and between the insulating members 103 and 104 by means of openings 111 and 112 in opposite sides of the insulating members 103 and 104. The contacts 106 and 107 are positioned on opposite sides of the shaft 110 to receive the bar 113 when the main contacts are open and contacts 108 and 109 are positioned on opposite sides of the bar to receive the shorting bar 113 when the main contacts are closed. In the lower position the bar connects the contacts 108 and 109 and in the upper position connects the contacts 106 and 107. The split contacts are respectively connected to the terminals 114; 115, 116 and 117 fitting in suitable channels in the members 103 and 104. The splitter contact head is secured to the fixed head by means of bolts 118 passing through the insulating members 103 and 104 and threadedv in nut 119 fitting in recess 120 with slot 121 for passing the bolt 118. Thus, the splitter contact 16 is securely mounted to the head 11.

The shaft 110 is made of an insulating material and is moved linearly by the counterweight 80. The counterweight has a laterally extending member 84 with a finger portion fitting in the slot 122 of the jaw-like member 123 secured to the end of the bar 110. A spring clip124. is provided on the finger portion to fit in the slot 122 to press the side of the finger into engagement with the side of the slot. The shaft is moved up and down by the counterweight 80 in response to the operation of the electromagnetic unit. When the contacts 73, 74 are in engagement with the contacts 24 and 25, the shorting bar 113 is in engagement with the split contacts 108 and 109 and when the contacts 73, 74 are separated from the contacts 24, and 25, the shorting bar 113 is in engagement with split contacts 106 and 107. The shaft 110 remains in engagement with a respective pair of contacts for a substantial, distance of the movement of the shaft 110 to maintain a current transfer relationship between the bar 113 and the splitter contacts for a large distance of the movement of the plunger 13. Thus, under a severe physical shock, some movement of the shaft 110 will not produce a disengagement of the shorting bar 113.

The contacts 108 and 109 through the external terminals 116 and 117 are connected to the terminals of the starting button so that when the plunger is raised in an engaging position, the shorting bar is lowered to bridge the shorting contacts. On application of a physical shock to the connector, the shorting bar remains in engagement with the contacts 108 and 109 maintains the energization of the unit. Also, when the plunger is in a disengaged position, any shock applied to the connector will prevent energization of the coil due to balancing action of the counterweight.

The Weight of hte plunger is counterbalanced by the counterweight 80 so that about the shaft 94 the weights of the two mechanisms are balanced and the movement of the plunger with the movable contact head in one direction is resisted by the weight 80 attempting to move in the opposite direction. Thus, the application of a physical blow having a vertical component will not disturb the engagement or disengagement of the main contacts.

The splitter type contact maintains closure on the application of a lateral force due to the bayonet type construction, and a longitudinally applied force the shorting bar remains in engagement with the contacts for a considerable portion of the stroke so that any movement produced by a jarring action would not break the contact. Thus, the combination of a stabilized plunger and the maintenance of the shorting contacts produces a contactor that may be subjected to severe physical shock. Although the contactor is designed for operation in a normally vertical position, it is also operable at a substantial incline to the vertical with the same stabilizing eifect as described.

Various other-modifications and changes may be made in the bql nlcnts and in the invention as described without departing from the invention as set forth in the appended claims.

I claim:

1. An electrical contactor comprising a panel, an insulator head having fixed contacts therein, a solenoid having a plunger reciprocally mounted in said solenoid carrying contacts movable in and out of engagement with said fixed contacts, a frame for supporting said solenoid spaced from said panel, a counterweight having rectangularly shaped sides and said frame having spaced members ex tending between said panel and said solenoid, said members having channels and said counterweight fitting in said channels to guide the counterweight in a linear reciprocal motion in opposition to the movement of said plunger, and means for connecting said plunger and counterweight to counteract any rapid movement or shock applied to said plunger and prevent movement of said movable contacts in or out of engagement with said fixed contacts.

2. An electrical contactor as set forth in claim l where in said connecting means comprises a supporting frame secured to said panel below said plunger and said counterweight, a shaft positioned on said frame between said plunger and said counterweight, a rotatable link mounted on said shaft and connected to said plunger and said counterweight on opposite sides of said shaft, and resilient means engaging said side members and said link to reciprocally hold said plunger member in a spaced relation to said fixed contacts.

3. An electrical contactor as set forth in claim 2 wherein said plunger has a member pivotally mounted on the end thereof to move transversely to said shaft, and said counterweight has a portion extending downwardly, said rotatably mounted link formed of two pieces positioned on opposite sides of said pivotally mounted member and said counterweight extending portion to provide laterally spaced connections to said plunger and counterweight for application of actuating forces thereto.

4. An electrical contactor comprising a panel, an insulator head having fixed contacts therein, a solenoid having a plunger reciprocally mounted in said solenoid carrying contacts movable in and out of engagement with said fixed contacts, a splitter-type contact having two sets of contacts and a shorting bar for connecting the respective contacts of a set, an insulating shaft reciprocally extending between the contacts of a set to move said shorting bar in and out of engagement with a respective set and means for coupling said shaft with said plunger for moving said shorting bar out of contact with one set of contacts and into contact with the other set of contacts as the movable contacts on the plunger are moved in and out of engagement, a frame for supporting said solenoid spaced from said panel, a counterweight reciprocally positioned between said solenoid and said panel to move in opposition to the movement of said plunger, and means for connecting said plunger and counterweight to counteract any rapid movement or shock applied to said plunger to maintain said splitter contact in a solenoid energizing condition thereby preventing the opening of said fixed contacts.

5. An electrical contactor as set forth in claim 4 wherein a member extends laterally to said counterweight and is secured thereto and extends adjacent said shaft and has means for flexibly coupling said laterally extending member and said shaft for actuation of said shorting bar in response to the movement of said counterweight.

6. An electrical contactor comprising an insulator head having two spaced fixed contacts and a movable bridging contact for coupling said fixed contacts to pass current therethrough, two spaced fixed second contacts and a second bridging contact having a long contact stroke with said second fixed contacts for maintaining the energization of the solenoid, a solenoid having a plunger reciprocally mounted therein and carrying said first bridging contact for movement in and out of engagement with said first fixed contacts, counterbalancing means reciprocally mounted to move in opposition to the movement of said plunger and having means for connecting said counterbalancing means and said plunger to stabilize said plunger under shock conditions and having means for actuating said second bridging contact into engagement with said second fixed contact on energization of said solenoid to maintain the energization of said solenoid under shock conditions.

References Cited in the file of this patent UNITED STATES PATENTS 556,311 Esrnond Mar. 10, 1896 709,814 Coleman Sept. 23, 1902 2,165,037 Ellis et al July 4, 1939 2,378,162 Stapleton June 12, 1945 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N00 4, September 15, 1959 Robert L Clerk It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 52, iior "lite" we W line 63, after "and."

insert on Signed and sealed this 8th day of March 1969.,

(SEAL) Attest:

KARL H. .AXLINE ROBERT C. WATSON Attesting Officer Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N0o 2,904,657 September l5, 1959 Robert L Clark It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should readas corrected below.

Column 4, line 52, for "late" read me 5 line 63, after "and."

insert on Signed and sealed this 8th day of 1960 (SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Officer Commissioner of Patents 

